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Java example source code file (CompileTheWorld.java)

This example Java source code file (CompileTheWorld.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

compiletheworld, ctw, currentthreadexecutor, done, executorservice, interruptedexception, ioexception, list, override, printstream, runtimeexception, string, threading, threadpoolexecutor, threads, timeunit, util

The CompileTheWorld.java Java example source code

/*
 * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package sun.hotspot.tools.ctw;

import sun.management.ManagementFactoryHelper;

import java.io.*;
import java.nio.file.Files;
import java.nio.file.Paths;

import java.util.List;
import java.util.concurrent.*;

public class CompileTheWorld {
    /**
     * Entry point. Compiles classes in {@code args}, or all classes in
     * boot-classpath if args is empty
     *
     * @param args paths to jar/zip, dir contains classes, or to .lst file
     *             contains list of classes to compile
     */
    public static void main(String[] args) {
        String logfile = Utils.LOG_FILE;
        PrintStream os = null;
        if (logfile != null) {
            try {
                os = new PrintStream(Files.newOutputStream(Paths.get(logfile)));
            } catch (IOException io) {
            }
        }
        if (os != null) {
            System.setOut(os);
        }

        try {
            try {
                if (ManagementFactoryHelper.getCompilationMXBean() == null) {
                    throw new RuntimeException(
                            "CTW can not work in interpreted mode");
                }
            } catch (java.lang.NoClassDefFoundError e) {
                // compact1, compact2 support
            }
            String[] paths = args;
            boolean skipRtJar = false;
            if (args.length == 0) {
                paths = getDefaultPaths();
                skipRtJar = true;
            }
            ExecutorService executor = createExecutor();
            long start = System.currentTimeMillis();
            try {
                String path;
                for (int i = 0, n = paths.length; i < n
                        && !PathHandler.isFinished(); ++i) {
                    path = paths[i];
                    if (skipRtJar && i > 0 && isRtJar(path)) {
                        // rt.jar is not first, so skip it
                        continue;
                    }
                    PathHandler.create(path, executor).process();
                }
            } finally {
                await(executor);
            }
            System.out.printf("Done (%d classes, %d methods, %d ms)%n",
                    Compiler.getClassCount(),
                    Compiler.getMethodCount(),
                    System.currentTimeMillis() - start);
        } finally {
            if (os != null) {
                os.close();
            }
        }
    }

    private static ExecutorService createExecutor() {
        final int threadsCount = Math.min(
                Runtime.getRuntime().availableProcessors(),
                Utils.CI_COMPILER_COUNT);
        ExecutorService result;
        if (threadsCount > 1) {
            result = new ThreadPoolExecutor(threadsCount, threadsCount,
                    /* keepAliveTime */ 0L, TimeUnit.MILLISECONDS,
                    new ArrayBlockingQueue<>(threadsCount),
                    new ThreadPoolExecutor.CallerRunsPolicy());
        } else {
            result = new CurrentThreadExecutor();
        }
        return result;
    }

    private static String[] getDefaultPaths() {
        String property = System.getProperty("sun.boot.class.path");
        System.out.println(
                "# use 'sun.boot.class.path' as args: " + property);
        return Utils.PATH_SEPARATOR.split(property);
    }

    private static void await(ExecutorService executor) {
        executor.shutdown();
        while (!executor.isTerminated()) {
            try {
                executor.awaitTermination(Long.MAX_VALUE, TimeUnit.NANOSECONDS);
            } catch (InterruptedException ie) {
                Thread.currentThread().interrupt();
                break;
            }
        }
    }

    private static boolean isRtJar(String path) {
        return Utils.endsWithIgnoreCase(path, File.separator + "rt.jar");
    }

    private static class CurrentThreadExecutor extends AbstractExecutorService {
        private boolean isShutdown;

        @Override
        public void shutdown() {
            this.isShutdown = true;
        }

        @Override
        public List<Runnable> shutdownNow() {
            return null;
        }

        @Override
        public boolean isShutdown() {
            return isShutdown;
        }

        @Override
        public boolean isTerminated() {
            return isShutdown;
        }

        @Override
        public boolean awaitTermination(long timeout, TimeUnit unit)
                throws InterruptedException {
            return isShutdown;
        }

        @Override
        public void execute(Runnable command) {
            command.run();
        }
    }
}

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